U.S. patent number 10,363,501 [Application Number 15/682,039] was granted by the patent office on 2019-07-30 for magnetic filter for a central heating system.
This patent grant is currently assigned to ADEY HOLDINGS (2008) LIMITED. The grantee listed for this patent is ADEY HOLDINGS (2008) LIMITED. Invention is credited to Simon Downie, Kashem Pathan.
United States Patent |
10,363,501 |
Downie , et al. |
July 30, 2019 |
Magnetic filter for a central heating system
Abstract
A magnetic filter 10 includes first and second separation
chambers 10, 12. The separation chambers 10, 12 each have an inlet
and an outlet, and the separation chambers 10, 12 are joined
together such that the inlets of the first and second chambers are
adjacent, and the outlets of the first and second chambers are
adjacent. An inlet port arrangement 28 connects both inlets to a
single inlet pipe, and an outlet port arrangement 30 connects both
outlets to a single outlet pipe.
Inventors: |
Downie; Simon (Cheltenham,
GB), Pathan; Kashem (Worcester, GB) |
Applicant: |
Name |
City |
State |
Country |
Type |
ADEY HOLDINGS (2008) LIMITED |
Cheltenham, Gloucestershire |
N/A |
GB |
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Assignee: |
ADEY HOLDINGS (2008) LIMITED
(Cheltenham, GB)
|
Family
ID: |
52821836 |
Appl.
No.: |
15/682,039 |
Filed: |
August 21, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170340994 A1 |
Nov 30, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15552271 |
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PCT/GB2016/050186 |
Jan 28, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16L
27/12 (20130101); B01D 21/0009 (20130101); B01D
21/2411 (20130101); F24H 9/0047 (20130101); B01D
35/06 (20130101); F24D 19/0092 (20130101); F24H
9/0005 (20130101); B03C 1/0332 (20130101); B01D
2221/02 (20130101); B03C 1/286 (20130101); F16L
27/125 (20130101); B01D 21/267 (20130101); B03C
2201/18 (20130101); B03C 2201/28 (20130101) |
Current International
Class: |
B01D
35/06 (20060101); F24D 19/00 (20060101); F16L
27/12 (20060101); F24H 9/00 (20060101); B01D
21/24 (20060101); B03C 1/28 (20060101); B03C
1/033 (20060101); F28F 19/01 (20060101); B01D
21/00 (20060101); B01D 21/26 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1135747 |
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Nov 1982 |
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CA |
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201496693 |
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Jun 2010 |
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CN |
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202091683 |
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Dec 2011 |
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CN |
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203309421 |
|
Nov 2013 |
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CN |
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19711074 |
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Sep 1998 |
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DE |
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2258602 |
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Aug 1975 |
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FR |
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2306716 |
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Nov 1976 |
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FR |
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2242247 |
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Sep 1991 |
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GB |
|
2476825 |
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Jul 2011 |
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GB |
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2476825 |
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Jul 2011 |
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GB |
|
2491246 |
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Nov 2012 |
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GB |
|
2500908 |
|
Oct 2013 |
|
GB |
|
2518162 |
|
Mar 2015 |
|
GB |
|
2012073029 |
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Jun 2012 |
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WO |
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Primary Examiner: Ramdhanie; Bobby
Assistant Examiner: Anderson; Denise R.
Attorney, Agent or Firm: Dockins; Michael E. Shumaker, Loop
& Kendrick, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser.
No. 15/552,271 Filed on Aug. 19, 2017, and claims the benefit of
priority of, international application Serial No. PCT/GB2016/050186
filed on Jan. 28, 2016 hereby incorporated herein by reference in
its entirety which claims the benefit of GB1502756.8 filed on Feb.
19, 2015 and GB1521054.5 filed on Nov. 30, 2015, each of which is
incorporated herein by reference in its entirety.
Claims
We claim:
1. A magnetic filter for a central heating system, the magnetic
filter including: a first separation chamber having a first inlet
and a first outlet, and a first magnet disposed on a first axis
within the first separation chamber, the first separation chamber
being substantially cylindrical; a second separation chamber having
a second inlet and a second outlet, and a second magnet disposed on
a second axis within the second separation chamber, the second
separation chamber being substantially cylindrical, the first
separation chamber and the second separation chamber being disposed
next to each other, and longitudinal sides of the first separation
chamber and the second separation chamber being joined together to
provide the first and second separation chambers on different
longitudinal axes, the first inlet of the first separation chamber
being disposed adjacent the second inlet of the second separation
chamber, and the first outlet of the first separation chamber being
disposed adjacent the second outlet of the second separation
chamber, the magnetic filter further including an inlet port
arrangement between the first separation chamber and the second
separation chamber for fluidly connecting the first inlet of the
first separation chamber and the second inlet of the second
separation chamber to a single inlet pipe, and an outlet port
arrangement between the first separation chamber and the second
separation chamber for fluidly connecting the first outlet of the
first separation chamber and the second outlet of the second
separation chamber to a single outlet pipe, the inlet port
arrangement and the outlet port arrangement being provided on the
same side of the filter, wherein a flow deflector is provided
between the first separation chamber and the second separation
chamber for splitting a flow through the inlet port arrangement
into a first portion of flow entering the first separation chamber
at a tangent, creating a first swirl of flow in the first
separation chamber, and a second portion of flow entering the
second separation chamber at a tangent, creating a second swirl of
flow in the second separation chamber, the first swirl of flow and
the second swirl of flow swirling in opposing directions, and in
use, the first magnet and the second magnet each filter magnetic
particles from water of the of the central heating system as the
water circulates through the central heating system, including
through the magnetic filter from the inlet port arrangement to the
outlet port arrangement.
2. A magnetic filter as claimed in claim 1, in which the first
magnet is provided in a centre of the first separation chamber,
and/or the second magnet is provided in a centre of the second
separation chamber.
3. A magnetic filter as claimed in claim 1, in which the first
inlet of the first separation chamber is in a first curved wall of
the first separation chamber, and the second inlet of the second
separation chamber is in a second curved wall of the second
separation chamber.
4. A magnetic filter as claimed in claim 3, in which the inlet port
arrangement fluidly connects to the first inlet of the first
separation chamber and to the second inlet of the second separation
chamber at a tangent to the first curved wall and at a tangent to
the second curved wall, respectively.
5. A magnetic filter as claimed in claim 1, in which the first
outlet of the first separation chamber is in a first curved wall of
the first separation chamber, and the second outlet of the second
separation chamber is in a second curved wall of the second
separation chamber.
6. A magnetic filter as claimed in claim 5, in which the outlet
port arrangement fluidly connects to the first outlet of the first
separation chamber at a tangent to the first curved wall, and
wherein the outlet port arrangement fluidly connects to the second
outlet of the second separation chamber at a tangent to the second
curved wall.
7. A magnetic filter as claimed in claim 1, in which the inlet port
arrangement and the outlet port arrangement each include a
substantially Y-shaped flow path.
8. A magnetic filter as claimed in claim 1, in which the flow
deflector has a curved profile.
Description
FIELD OF THE INVENTION
The present invention relates to a magnetic filter for a central
heating system, and in particular to a filter for use in a system
having pipework with diameter between around 35 and 42 mm.
BACKGROUND TO THE INVENTION
It is now common to fit filter devices to central heating systems,
to remove magnetic and non-magnetic particles from the system water
as it circulates around the system. Such filters are useful in all
types of central heating system, from small domestic systems with a
single circuit and a few radiators, to the largest systems in
factories and other industrial sites.
At present, filters are available for domestic systems, which
typically use 22 mm or 28 mm copper pipe for the main heating
circuit(s). These filters typically have a body made from plastics,
for example, glass-reinforced nylon. Various features are known
which provide for easy and compact installation in a domestic
setting. For example, the Applicant's co-pending application
published as GB2502383 discloses an in-line fitment for a filter
which includes two sockets, one socket having a greater pipe
receiving depth than the other socket. Where some manipulation of
the pipework is possible, this provides for easy attachment of the
fitment to the heating circuit, where the parts of the fitment
which attach to the filter are guaranteed to be at exactly the
correct spacing for attachment of the filter.
Filters are also available for larger systems, which use 2 inch
(around 50 mm) or greater diameter pipe for the heating circuit(s).
For example, the filters sold under the trade mark "Magnaclean.RTM.
Commercial" fit into this category. These filters are essentially
in the form of a large, heavy, cast container, with an inlet and an
outlet on either side, a removable lid, and magnets extending into
the container to attract and retain magnetic particles from system
water as it flows through the filter. These large filters are
typically connected into the heating circuit by providing a welded
flange on the inlet and outlet of the filter. A similar flange can
be welded onto the pipe ends to be connected, and each pipe flange
is then bolted to its corresponding filter flange, some sealing
material having been placed in between.
However, there is a class of medium-sized central heating systems
for which neither of these types of filters are particularly well
suited. These systems typically use steel pipe, between 35 mm and
42 mm in diameter. The pipes are usually joined either by tapered
threads, which are typically made as required using a die, or by
crimping, for example using the "XPRESS".RTM. crimping system.
These pipes are inflexible, which makes it impossible to use the
in-line fitment as described in GB2502383. Also, the size of the
tools used, and the forces typically applied to pipework during
installation of these systems, makes damage to a plastic-bodied
filter likely. However, large filters such as the Magnaclean.RTM.
Commercial are expensive to manufacture, and rather over-specified
in terms of the system pressure and flow rate which is typical in
medium-sized (35-42 mm) systems.
It is an object of this invention to provide a magnetic filter
which is suitable for use in these medium-sized central heating
systems.
STATEMENT OF INVENTION
According to a first aspect of the present invention, there is
provided a telescopic fitment for connection of a magnetic filter
into a central heating system circuit, the telescopic fitment
including a first connector and a second connector, each of the
first and second connectors including a filter connection end for
connecting with the magnetic filter and a circuit connection end
for connecting with the central heating system circuit, at least
one of the first and second connectors including an inner pipe and
an outer pipe, the filter connection end being provided on one of
the inner or outer pipes and the circuit connection end being
provided on the other of the inner or outer pipes, the inner pipe
being slideable within the outer pipe for adjusting the position of
the circuit connection end with respect to the filter connection
end, whilst maintaining a sealed fluid path between the circuit
connection end and the filter connection end.
The telescopic fitment is especially well-suited for use with
pipework having a diameter between around 35 mm and 42 mm. This
pipework is typically joined by the use of a tapered male thread
which mates with a straight female thread. The circuit connection
end may be provided with a straight female thread, and may be then
tightened onto a tapered thread on the end of a pipe which forms
part of the heating circuit. As the threads are tightened, the
circuit connection end will move slightly along the tapered thread
of the pipe. At some point, the connection will be tight enough to
form a seal. The other connector, which may include a similar
telescopic arrangement, may be tightened onto another pipe in
exactly the same way. Because the connectors are telescopically
adjustable, the fitment can be connected to pipework having a range
of relative distances and positions between the two connections to
the heating circuit. Also, the tapered thread connection method as
described above may be used, without having to predict precisely
how far along the tapered thread the joint will tighten and
seal.
35-42 mm diameter pipes are typically made from steel, and are very
inflexible. The telescopic fitment therefore provides a similar
level of flexibility in terms of positioning and alignment as is
typically achievable in smaller (e.g. 22 mm copper) systems, where
there is normally some movability in an unconnected pipe end.
The circuit connection end may be provided on the outer pipe and
the filter connection end may be provided on the inner pipe.
At least one of the outer and inner pipes may be substantially in
the form of a 90 degree elbow. Magnetic filters typically have
ports which extend parallel to each other, and yet they are usually
to be fitted essentially to a single straight pipe where a section
has been cut out to accommodate the filter. In other words,
magnetic filters are usually attached to pipe ends which are facing
each other, in-line with each other.
Nevertheless filters in some cases need to be fitted to two
parallel pipes, or to pipe ends at various angles relative to each
other. It is therefore envisaged that the fitment of the invention
may be provided in a range of alternatives to accommodate these
requirements.
An O-ring seal may be provided between the inner and outer pipes of
the or each telescopic connector. Preferably, two O-ring seals are
provided to ensure a leak-proof join.
The O-ring seal(s) may be provided in groove(s) on the inner pipe,
and the outer pipe may have a substantially smooth inside wall at
the point where it meets the seal in use.
A stop may be provided between the inner and outer pipes, to
prevent the outer pipe from sliding off the inner pipe and
detaching. Where an O-ring or double O-ring seal is provided, the
stop may prevent the outer pipe from sliding to a point where the
seal is no longer between the two pipes.
Preferably, the stop is in the form of a snap ring which is held
within a groove extending around the interior of the end of the
outer pipe, and a first circumferential detent on the exterior wall
of the inner pipe. The snap ring, when held in its groove, forms a
circumferential bulge on the interior wall of the inner pipe, and
the first detent on the inner pipe obstructs that bulge and
prevents the outer pipe from moving past the detent.
The use of the snap ring to form part of the stop is particularly
advantageous, because it allows for easy assembly of the telescopic
fitting. A snap-ring assembly groove may be provided on the
exterior wall of the inner pipe, further inward (that is, away from
the end of the inner pipe over which the outer pipe is slid) than
the first detent. Just inward of the snap-ring assembly groove, an
extension may be provided around the external wall of the inner
pipe which forms a second detent.
The outer pipe preferably has a tapered interior wall at the end
which is to be slid over the inner pipe, giving that end of the
outer pipe a mouth which is slightly wider than the diameter of the
rest of the outer pipe. The groove within which the snap ring is
held is preferably located just inward (i.e. in the direction away
from the end which is slid over the inner pipe) of the tapered
mouth.
To assemble the connector, firstly a metal snap ring may be placed
around the inner pipe, either over the snap-ring assembly groove or
over the inner pipe at any position between the first detent and
the snap-ring assembly groove. The outer pipe may then be slid over
the inner pipe, past the seals. The tapered mouth of the outer pipe
will slide over the snap ring, and the snap ring will then be
carried with the outer pipe until it reaches the snap-ring assembly
groove. When the snap ring is located over the snap-ring assembly
groove, the outer pipe can continue to be pushed a short distance
further onto the inner pipe. As it is, the tapered mouth will start
to compress the snap-ring into the snap-ring assembly groove, until
the outer pipe has moved to the point where the snap-ring holding
groove on the outer pipe is level with the snap-ring assembly
groove on the inner pipe. At this point, the snap-ring will expand
into the snap-ring holding groove, and the outer pipe can be
extended back out, carrying the snap ring with it.
At this stage, the telescopic connector is assembled, and cannot
easily be disassembled, since there is no way of removing the
snap-ring from within the snap-ring holding groove. The snap-ring
effectively becomes a permanent part of the outer pipe, and
prevents the outer pipe from moving past the point where the
snap-ring is obstructed by the first detent on the inner pipe.
Note that, after assembly, the snap-ring assembly groove serves
essentially no further purpose.
The filter connection end of each connector may include an
arrangement whereby part of the connector is received within an
inlet/outlet port of the magnetic filter, and a threaded ring is
provided which can be tightened by hand to retain the connector in
attachment with the magnetic filter. Such an arrangement is
disclosed in the Applicant's co-pending British patent application
No. 1404432.5, which is incorporated herein by reference.
The fitment may be provided with a magnetic filter, the magnetic
filter including inlet and outlet ports which extend from the
filter substantially parallel with each other. The inlet and outlet
ports may be externally screw-threaded for connection with the
filter connection ends of the connectors, as described above.
Typically, the connectors of the fitment are substantially 90
degree elbows, and when the filter connection ends are attached to
the parallel inlet and outlet ports of the filter the connectors
can be configured so that their circuit connection ends face away
from each other, and are disposed along the same line. The
telescopic arrangement as described may be provided substantially
on the circuit connection ends of the connectors, so that the
distance between the circuit connection ends of the connectors is
adjustable when they are connected to the filter as described. The
filter may then be installed on a straight pipe by cutting a
section out of the pipe, and then adjusting the telescoping
components of the connectors so that the fitment is exactly the
right size to fit the length of pipe which has been removed. The
circuit connection ends of the connectors may be internally screw
threaded, in which case they may be connected into the circuit by
cutting a tapered thread into the ends of the heating circuit pipes
with a die tool, and then screwing the circuit connection ends of
the connectors onto the tapered threads. Alternatively, the circuit
connection ends of the connectors may be crimped into the central
heating circuit, for example using the XPRESS.RTM. crimping
system.
According to a second aspect of the invention, there is provided a
filter for a central heating system, the filter including at least
one separation chamber and a screw-top closure for closing an
opening in the separation chamber, the screw-top closure having a
circumferential wall, and the circumferential wall being provided
with castellations around an interior side of the wall for engaging
with a handle member which can be placed across the screw-top,
between opposing sides of the interior wall, to allow the screw-top
closure to be turned by hand.
A screw-top closure or lid having interior castellations for
engagement with a handle is advantageous in a filter for a
medium-sized (35-42 mm) heating system, because it allows the body
and closure of the separation chamber to be made from plastics, for
example glass-reinforced nylon, while mitigating the risk of
overtightening, which can damage threads and seals. Overtightening
is a particular risk when installing or modifying systems of this
size, because the tools used on other parts of the system tend to
be heavy-duty, for use on steel pipe. However, the screw-top lid
with interior castellations can be constructed in a way which makes
it impossible to engage an ordinary spanner. The installer must
therefore use the provided handle, which is designed to be operated
by hand or by relatively small tools (for example a 22 mm spanner
or socket wrench) so that the lid is closed with the correct
torque.
Preferably, an exterior thread is provided on the outside of the
circumferential wall, opposite the castellations. The thread may
extend substantially to the top of the wall, so that when the
screw-top is screwed into the separation chamber there is little or
no protrusion of the lid above the top of the chamber. This
prevents the lid from being forced with a spanner or similar tool.
However, a lip may be provided, extending outwardly from the top of
the circumferential wall. The lip may act as a stop to prevent the
lid from being screwed too far into the separation chamber, and may
sit against an edge of a wall of the separation chamber when the
lid is screwed into the chamber.
A positioning aid may be provided substantially at the centre of
the lid, extending from the lid in the same direction as the
circumferential wall. The positioning aid may be in the form of a
substantially circular protrusion, for engaging with a
corresponding circular indent in the provided handle. The handle
may therefore be oriented in substantially any direction across the
centre of the lid, subject to it engaging with castellations on
opposite sides of the circumferential wall. The castellations are
preferably equally spaced substantially all the way around the
interior surface of the circumferential wall.
The positioning aid may be part of a bleed valve or other fitting
which may be usefully provided in the lid.
The filter may be provided with a handle member in the form of an
elongate body, having a top side, a bottom side and two opposing
end faces, and engagement means on each end face for engaging with
the castellations on the wall of the lid. The engagement means may
be in the form of rectangular cut-outs in each end face of the
handle member, which extend to at least one edge of each respective
end face. That is, the rectangular cut-outs are open at at least
one of the top side and the bottom side of the handle body.
Preferably, the elongate cut-outs do not extend as far as the
opposite edge of each respective face, so that the cut-outs are
closed at one of the top side and the bottom side of the handle
body. Effectively this means that, in use, part of the elongate
handle will sit on top of the castellations of the lid, and part of
the handle will extend between the castellations.
The handle member may include an indent substantially at the centre
of one side of the body, for fitting over a positioning aid as
described above. Preferably, the indent is substantially circular.
Preferably, the indent is on one of the top and bottom sides, and
extends only part way towards the other side, although in some
embodiments the indent may be in the form of a through-hole, from
one side of the handle body to the other.
Although it is envisaged that the handle member will usually be
turned by hand, engagement means for engaging a spanner or socket
wrench may be provided. The engagement means may be sized to fit a
suitable spanner or wrench, for example 22 mm between flats, which
is likely to have a short enough handle that damage due to
overtightening is unlikely. The engagement means provide the option
of using a spanner for extra leverage when loosening the closure,
if it has become tight over time. However, the types of tools which
can be used are restricted by the size of the engagement means, and
the arrangement still serves to discourage use of very large tools
which could cause damage by overtightening.
A socket for engaging a nut or bolt head may be provided on one of
the top and bottom sides of the handle body, preferably on the same
side of the body as the positioning indent and preferably between
the positioning indent and the end of the handle. In some
embodiments, two sockets may be provided, one on either side of the
positioning indent. Where two sockets are provided, they may be
identical or they may be different shapes or sizes for engaging
different nuts and bolts. It is also possible to provide sockets on
both sides of the handle body, so that three or four different
sockets might be provided in total.
The filter may be provided with a drain valve on a bottom end of
the separation chamber, and the drain valve may be closed by a
drain plug in the form of a bolt which is sized to be operated by
engaging the socket of the handle member.
The handle member may have left and right side faces which extend
between the top and bottom faces, and also between the two end
faces. A further socket may be provided on at least one, or
preferably both, of the left and right side faces. The further
socket in some embodiments is a square socket, as is typical for
operating bleed valves. A bleed valve may be provided on the lid of
the separator, and may be sized to fit the further socket on the
handle.
According to a third aspect of the invention, there is provided a
magnetic filter for a central heating system, the magnetic filter
including:
a first separation chamber having an inlet and an outlet, and a
magnet disposed within the separation chamber,
a second separation chamber having an inlet and an outlet, and a
magnet disposed within the separation chamber,
the first and second separation chambers being joined together, the
inlet of the first separation chamber being disposed adjacent the
inlet of the second separation chamber, and the outlet of the first
separation chamber being disposed adjacent the outlet of the second
separation chamber,
and the magnetic filter further including an inlet port arrangement
for fluidly connecting the inlets of the first and second
separation chambers to a single inlet pipe, and an outlet port
arrangement for fluidly connecting the outlets of the first and
second separation chambers to a single outlet pipe.
The arrangement of the invention may be used to provide for a
larger capacity filter, which is simple to fit and has the
advantages of smaller filters which are used in domestic or small
commercial systems, for example the filter disclosed in
GB1404432.5. The filter can be made from plastics, for example
glass-reinforced nylon, whilst providing a large enough
dirt-capturing capacity and a small enough pressure drop to be
suitable for use in 35-42 mm systems.
Preferably, each of the first and second separation chambers is
substantially in the form of a cylinder having circular or elliptic
cross-section. The magnet may be provided substantially in the
centre of the cylinder, so that water to be cleaned may flow around
the magnet on all sides. The inlet of each of the first and second
separation chambers is preferably in the curved wall of the
cylinder, and the inlet arrangement preferably fluidly connects to
each inlet substantially at a tangent to the curved wall. In other
words, the inlet arrangement extends away from each separation
chamber in a direction substantially in-line with the wall of the
separation chamber, at the point where the inlet arrangement meets
the curved wall.
Similarly, the outlet of each of the first and second separation
chambers is preferably in the curved wall of the cylinder, and the
outlet arrangement likewise may connect with each outlet
substantially at a tangent to the curved wall.
Having fluid flow into the separation chamber at a tangent causes a
swirl of flow within the separation chamber, which increases the
effectiveness of separation. At the same time, providing two
separation chambers next to each other means that a single inlet
port arrangement and outlet port arrangement may be provided for
the whole filter, and the inlet port arrangement may be disposed
substantially in-line with the outlet port arrangement, which
provides for easy connection of the inlet and outlet port
arrangements into pipework.
The inlet port arrangement and outlet port arrangement may each
include a substantially Y-shaped flow path, for splitting the flow
from the inlet port into two flow paths, one directed to each
separation chamber, and for combining the flow from the outlet of
each separation chamber into a single outlet port. The inlet and
outlet ports may be externally screw-threaded for connection to the
fitment of the first aspect of the invention.
DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, and to show
more clearly how it may be carried into effect, reference will now
be made by way of example only to the accompanying drawings, in
which:
FIG. 1 is a perspective view of a magnetic filter in accordance
with the second and third aspects of the invention, provided with a
telescopic fitment in accordance with the first aspect of the
invention;
FIG. 2 is an exploded perspective view of the magnetic filter and
fitment of FIG. 1;
FIGS. 3a and 3b are cross-sections through the magnetic filter and
fitment of FIG. 1, showing the telescopic fitment in respectively
fully-extended and fully-retracted positions;
FIG. 4 is a magnified cross-section of part of the telescopic
fitment as shown in FIG. 3a;
FIG. 5 is a perspective view of a handle member for use with the
magnetic filter of FIG. 1;
FIGS. 6a and 6b are perspective views of the filter and fitment of
FIG. 1, shown together with the handle member of FIG. 5 in various
positions; and
FIGS. 7 and 8 are cross-sections through the magnetic filter and
fitment of FIG. 1, with FIG. 7 showing the direction of flow within
the fitment and filter adjacent a first connector and FIG. 8
showing the direction of flow with the fitment and filter adjacent
a second connector.
DESCRIPTION OF A PREFERRED EMBODIMENT
Referring firstly to FIGS. 1 and 2, a magnetic filter for a central
heating system is indicated generally at 10, and is shown with a
fitment 60.
The magnetic filter includes first and second substantially
cylindrical separation chambers 12, 14. The first separation
chamber 12 has a first curved wall 12a (see FIG. 7). The second
separation chamber 14 has a second curved wall 14a (see FIG. 7).
Each chamber is open at one end (uppermost in FIG. 1), but the open
end of each separation chamber 12, 14 is closed by a closure 16,
18. In FIG. 1 the closures 16, 18 are shown fully fitted onto the
separation chambers 12, 14. In other words, the magnetic filter 10
is shown closed, as it would be when installed in a central heating
system and in normal use.
As best seen in FIG. 2, magnets 20, 22 extend into each of the
separation chambers 12, 14. The magnets 20, 22 are fixed to the
closures 16, 18 and are enclosed in use by sleeves 24, 26. The
arrangement of a magnet attached to a closure, and the sleeves
themselves, are described in detail in co-pending application
GB1404432.5, which is incorporated herein by reference.
An inlet port arrangement 28 and outlet port arrangement 30 are
provided, between the first and second separation chambers 12, 14.
FIG. 7 shows a first inlet 28a to the first separation chamber 12
and a first inlet 28b to the second separation chamber 14. FIG. 8
shows a first outlet 30a from the first separation chamber 12 and a
second outlet 30b from the second separation chamber 14. The first
and second separation chambers 12, 14 are disposed next to each
other and are joined to each other, and the inlet and outlet port
arrangements are provided between the two separation chambers. The
two separation chambers 12, 14, and the inlet and outlet port
arrangements 28, 30 are moulded from glass-reinforced nylon in a
single piece.
The inlet and outlet port arrangements 28, 30 are externally
screw-threaded.
Each closure 16, 18 is in the form of a substantially planar roof
section 40, 42, and a circumferential wall 44, 46 extending from
the roof section. An external screw thread 36, 38 is provided on
the outside of each circumferential wall 44, 46, and castellations
48, 50 are provided on the inside of the wall. The castellations
48, 50 extend substantially radially and inwardly from the inside
of the wall, and are in the form of spaced elements around the
interior of the wall. A bleed valve 52, 54 is provided
substantially in the centre of each roof section 40, 42.
Near the top of the curved wall of each of the separation chambers
12, 14, an internal screw thread 32, 24 is provided. The internal
screw threads 32, 34 correspond with external screw threads 36, 38
on the closure members 16, 18. Hence the closure members 16, 18 can
be screwed into the top of the separation chambers 12, 14, to form
a plug and seal the open end of the separation chambers.
A drain outlet is provided in the base of each separation chamber,
and a drain plug 56 substantially in the form of a bolt is provided
to close each drain outlet when the filter 10 is in use.
The fitment 60 comprises a first connector 62 and a second
connector 64. In this embodiment the connectors 62, 64 are
identical to each other, and are substantially in the form of 90
degree elbows. Each connector has a filter connection end 66 and a
circuit connection end 68. The circuit connection ends 68 of each
connector 62, 64 in use are connected into a central heating system
circuit, and the filter connection ends 66 are connected to the
magnetic filter 10, in particular to the inlet port arrangement 28
and the outlet port arrangement 30. As shown in FIG. 1, in use
system water flows into the filter via the uppermost connector 62
(arrow A) and flows out of the filter via the lowermost connector
64 (arrow B).
Referring now to FIGS. 3a, 3b, and 4, the fitment 60 will be
described in more detail.
The filter connection end 66 of each connector 62, 64 is
substantially identical to those disclosed in co-pending
application GB1404432.5, and is not described in detail here.
Briefly, the filter connection end includes a fitment adapted to be
received within at least one of the ports of the separator, the
fitment including a bore for carrying fluid from/to the central
heating circuit to/from the separator, and a threaded connector for
securing the fitment to the or each port, the threaded connector
having a grip area for facilitating tightening of the connector by
hand.
The circuit connection end 68 is telescopic, and so can be extended
(as shown in FIG. 3a) and retracted (as shown in FIG. 3b) whilst
maintaining a sealed flow path between the circuit connection end
68 and the filter connection end 66. The telescopic components are
shown fully-extended in FIG. 3a, and fully retracted in FIG. 3b,
but it will be appreciated that the fitment 60 can also work with
the telescopic components in any intermediate position. Also, the
telescopic parts of each connector 62, 64 could be equally
extended, or have differing extents.
The telescopic circuit connection end 68 broadly includes an inner
pipe 70 and an outer pipe 72. The outer pipe slides over the inner
pipe to increase or decrease the total length of the circuit
connection end 68. As seen best in FIG. 4, two O-ring seals 74, 76
are provided in grooves near the end of the inner pipe 70. The
double seal ensures that fluid does not leak from the connector.
The outer pipe has a tapered mouth 78, and a groove 80 just inward
of the tapered mouth 78 which holds a snap-ring 82. The snap-ring
82 travels with the outer pipe 72 as it is moved (upwards and
downwards in FIG. 4) with respect to the inner pipe 70. A first
detent 84, in the form of a ring around the outside wall of the
inner pipe, stops the mouth 78 of the outer pipe sliding over the
O-ring seals 74, 76. The snap-ring 82 which is carried with the
outer pipe 72 is obstructed by the first detent 84 when the
telescopic parts are at maximum extension, preventing the parts
coming apart or compromising the seal.
A second detent 86 is provided on the outside of the inner pipe 70,
spaced some distance into the inner pipe 70 (i.e. towards the
filter connection end). Adjacent to the second detent 86 and
between the first and second detents 84, 86 is a snap-ring assembly
groove 88. The snap-ring assembly groove is used when assembling
the connector 64--the snap ring 82 can be placed around the inner
pipe 70, between the first detent 84 and the assembly groove 88.
The outer pipe 72 can then be pushed onto the inner pipe 70. As
this is done, the snap-ring will travel in the mouth 78 of the
outer pipe 72 until it reaches the assembly groove 88 and is
obstructed from further travel along the pipe (upwards in FIG. 4)
by the second detent 86. At this point, as the outer pipe 72 is
pushed slightly further over the inner pipe, the increasingly
narrow interior of the outer pipe 72 will compress the snap ring 82
into the groove 88, until the holding groove 80 of the outer pipe
72 is level with the snap ring 82. At this point, the snap ring 82
will snap into the holding groove 80, and the outer pipe 72 becomes
permanently fixed to the inner pipe 70.
The outer pipe 72 is the part which is joined into the heating
circuit. This may be via a screw connection in which case an
interior thread may be cut into the end of the outer pipe 72, or it
may be via a crimping system, or by any other means.
Referring now to FIGS. 5, 6a and 6b, a handle member is indicated
generally at 90. Note that although several handle members 90 are
shown in FIGS. 6a and 6b, this is merely to show the handle 90 in
different positions. It is envisaged that only one handle member 90
will be provided with each filter 10, since the handle 90 is a
multipurpose tool.
The handle member 90 is substantially elongate, having upper,
lower, left and right side faces 92, 94, 96, 98 and two opposing
end faces 100, 102. The lower face 94, the right side face 98 and
one of the end faces 102 are hidden in FIG. 5 but all faces are
shown in at least one of the positions in FIGS. 6a and 6b. In any
case, the left and right side faces 96, 98 are identical, as are
the two opposing end faces 100, 102.
On each opposing end face 100, 102, a rectangular cut-out or indent
104 is provided. The cut out extends all the way to the edge of the
end face 102, 104 which meets the lower face 94, but stops short of
each of the other three edges of the end face 102, 104. The
rectangular cut-out 104 on each end of the handle 90 is designed to
engage with the radial castellations 48, 50 which are provided on
the interior of the circumferential wall 44, 46 of each of the
closures 16, 18. When the handle 90 is engaged, it sits at least
partly below the top of the wall and castellations of the closure
16, 18, between opposing sides of the wall 44, 46. FIG. 6a shows
the handle in position to be engaged with closure 16 in this way,
indicated by arrow C.
A hexagonal male protrusion 111 is provided on the upper surface 92
of the handle 90, and is preferably sized at 22 mm across flats.
The hexagonal male protrusion 111 can be engaged with a socket
wrench or spanner which can then be used to apply torque to the
handle, if required.
When the handle is positioned between opposing sides of the
circumferential wall 44 of closure 16, it may be turned clockwise
or anticlockwise to tighten or loosen the closure 16, as required.
This can be done by hand or by using a socket wrench or spanner as
described above. Indeed, using any other tool is difficult. This is
an advantage, because where closures can be gripped by large
spanners or the like, overtightening is a risk and can lead to
damage to the plastic separation chamber, and to the seal of the
closure on the separation chamber. The handle generally allows
tightening and loosening of the closure 16 by hand, but over time
the closure may become tighter and more difficult to loosen by
hand. In that case, a socket wrench or spanner may be used.
However, the arrangement of the handle assembly provides a
practical limitation as to the types of tools which may be used,
therefore reducing the risk of damage caused by over-torquing.
On each side face 96, 98 of the handle member 90, a square socket
106 is provided within a substantially square extension 108. The
square socket is sized to operate bleed valve 52, and also other
bleed valves which are typically found on most radiators and other
central heating system components. The handle 90 is seen in the
correct position to operate the bleed valve 52 in FIG. 6a,
indicated by arrow D.
Two identical hexagonal sockets 110 are provided in the lower face
94 of the handle 90. These are best seen in FIG. 6a on the handle
90 indicated by arrow E. The sockets are disposed at either side of
a circular indent 112 which is substantially in the centre of the
lower face 94.
The hexagonal sockets 110 allow the handle to be used as a spanner
to operate the bolt 56 which forms the drain plug on the separator
chamber 14, as shown in FIG. 6b, indicated by arrow F.
Referring now to FIG. 7, the construction of the inlet arrangement
28 will be described in more detail. The flow path within the
outlet arrangement is substantially Y-shaped, the flow from the
inlet connector 62 through the inlet port being split into two,
part of the flow being directed into each of the first and second
separation chambers 12, 14. The inlet arrangement 28 is fluidly
connected with each separation chamber 12, 14 through an aperture
in the curved wall of the cylindrical separation chamber, and the
flow enters the separation chamber substantially parallel to the
curved wall, at the point where the curved wall meets the inlet
arrangement 28. In other words, flow enters each separation chamber
at a tangent. As a result, a swirl of flow is created in each of
the two chambers 12, 14, as indicated by arrows G.
The outlet arrangement 30 is not seen in the cross-section of FIG.
7, but it is substantially identical and, in fact, either port can
be used as the inlet, with the other port being used as the outlet.
Note that the flow deflector 114 which defines the centre of the
Y-shaped flow path in each inlet/outlet arrangement 28, 30 has a
curved profile in the plane defined by a circular section of the
cylinder--i.e. the plane in which the cross section of FIG. 7 is
shown. This reduces pressure drop which would otherwise be caused
at the outlet when the flow has to turn a sharp corner into the
substantially tangential outlet arrangement 30. It is found that,
with this size of filter, this arrangement gives acceptable results
in terms of pressure drop.
The filter and fitment provides for a high-performance and
economical filter which is useful in systems where a typical
domestic filter would be too small, and where a known commercial
filter would be over-specified and unnecessarily expensive. The
filter can be made from plastics, in particular glass-reinforced
nylon or glass-reinforced polypropylene, but safeguards are
provided against overtightening which can otherwise be a problem
with plastic filters of this size. The fitment arrangement allows
easy fitting to inflexible pipework.
The embodiments described above are provided by way of example
only, and various changes and modifications will be apparent to
persons skilled in the art without departing from the scope of the
present invention as defined by the appended claims.
* * * * *